#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <vector>
#include <algorithm>
#include <cstring>
#include <math.h>
using namespace std;
typedef long long ll;
int arr[50];
ll s = 0;
int cnt = 0;
int main()
{
	int i = 1;
	while (scanf("%d", &arr[i++]) != EOF)
	{
		cnt++;
	}
	for (int i = 1; i <= cnt; i++)
	{
		s += arr[i];
	}
	ll mi = 1;
	s = s * (mi << cnt - 1);
	printf("%lld", s);
	return 0;
}